The present invention relates to a turbo compressor, being mainly applied as an air source of power or into processes in a factory, and in particular, to a turbo compressor, being preferably applicable to that being constructed in three stages.
For all-purpose air compressors widely used within general industry fields, demands are made strongly upon small sizing of the turbo compressor, from requirements of lowering a cost and easiness in maintenance, etc. A requirement made upon fluid performances of the compressor is to achieve a predetermined discharge pressure at a predetermined suction flow rate. For fulfilling such the requirements, it is necessary to suppress or restrict the flow velocity of internal fluid, to be equal or less than a predetermined velocity or speed, by reducing the loss of motive power. As other requirements upon the compressor, it is that drain generating in an intercooler is prevented from being sucked from an outlet side of an intercooler into the compressor provided at the next-stage. For fulfilling such the requirement, it is necessary to suppress or restrict the flow velocity at the outlet of the intercooler, to be equal or less than a predetermined velocity or speed. However, such the requirements result into a compressor of large-scaled or large-sized.
For the purpose of achieving the down sizing of the compressor even under such the requirements as be contrary to the down sizing of the compressor, in the conventional turbo compressor, as was described, for example, in Japanese Patent Laying-Open No. 8-93685 (1996), the position is devised for each constituent element of the turbo compressor, so as to make the turbo compressor compact in size. In the compressor described in this publication, a rotation shaft is disposed in parallel with an output shaft of a driving motor through a gear apparatus. And, on both sides of the rotation shaft, a first-stage compressor and a second-stage compressor are connected to each other. Further, disposing the first-stage compressor on a side of the driving motor while the second-stage compressor on the opposite side thereof, a suction pipe and a suction filter of the first-stage compressor are positioned on a side of the driving motor.
Though the compressor mentioned in the conventional art, described in Japanese Patent Laying-Open No. 8-93685 (1996), can be made compact in sizes surely, but it is two (2) stage machine, therefore no consideration is paid into the structure for achieving the small sizing of the compressor, in particular, adopting three (3) stage structure, on which high pressure and much higher efficiency can be expected to obtain. Accordingly, there is made no consideration at all, on easiness in assembling and/or disassembling of the compressor if being structured as the three(3)-stage machine, and/or an improvement on workability thereof.
An object, according to the present invention, for dissolving such the drawbacks according to the conventional art as was mentioned in the above, is to provide a turbo compressor, being structured in three(3)-stages, but compact in sizes and easy in assembling and/or disassembling thereof.
According to the present invention, for accomplishing the objects mentioned above, firstly, there is provided a turbo compressor, comprising: a first rotation shaft, being connected to an output shaft of a driving motor, and having a first gear means thereon; a second rotation shaft, being disposed in parallel with said first rotation shaft, and having a second gear means engages with said first gear means; a third rotation shaft, being disposed in parallel with said first rotation shaft, and having a third gear means engages with said first gear means; first-stage and second-stage impellers, being attached onto both ends of said second rotation shaft; and a third impeller attached onto one end of said third rotation shaft, wherein operation gas is guided from the first-stage impeller to the second-stage impeller, and next to the third-stage impeller, further comprising: a first cooler for cooling the operation gas compressed by said first-stage impeller; a second cooler for cooling the operation gas compressed by said second impeller; a third cooler for cooling the operation gas compressed by said third impeller; and an integrated casing accommodating at least one of said first to third coolers therein, wherein at least one of said first to third coolers is aligned sequentially in direction substantially perpendicular to said first rotation shaft, and said integrated casing accommodates at least one of said first-stage, said second-stage and said third stage rotation shafts therein.
According to the present invention, preferably, in the turbo compressor, as described in above: wherein at least one of said first to third coolers is a corrugate fin-type cooler, and is disposed below said at least one of said first-stage to said third-stage impellers; wherein said first-stage impeller and said third-stage impeller are disposed on a side opposing to the driving, while said second-stage impeller is disposed on a side of the driving motor; and wherein said each cooler is accommodated within a refrigeration chamber divided in said integrated casing, and each flow path for guiding flow coming from the impeller to the refrigeration chamber, or for guiding flow coming out from the refrigeration chamber to the impeller, contains a straight line passing through a central axis of the impeller, excepting the flow path for guiding the flow from the first-stage impeller to the first cooler.
According to the present invention, preferably, in the turbo compressor, as described in the above: wherein said first-stage impeller is detachable while keeping said second rotation shaft held on said integrated casing, and further said second rotation shaft is detachable from said integrated casing while keeping said second-stage impeller attach on said second rotation shaft; wherein material of said first-stage impeller is selected to one of aluminum alloy, titanium alloy or steel; and wherein said each refrigeration chamber is formed in almost rectangular parallelepiped shape; said cooler has a sealing portion on an upper surface and a lower surface thereof, between the integrated casing defining the refrigeration chamber; the sealing portion divides the refrigeration chamber into a flow-in portion for the operation gas flowing into the cooler and a flow-out portion for the operation gas flowing out from the cooler; and a cross-section area on a cross-section perpendicular to the rotation shaft in the divided portion is equal or greater than that on the flow-in portion.
According to the present invention, preferably, in the turbo compressor, as described in above: wherein the cross-section areas on the flow-in portions are made smaller in an order: the refrigeration chamber, in which the first cooler is accommodated, the refrigeration chamber, in which the second cooler is accommodated, and the refrigeration chamber, in which the third cooler is accommodated; wherein said cooler is made up by laminating layers alternately, in which cooling fluid or being-cooled fluid flows; the cooling fluid and the being-cooled fluid flowing in each the layer are intersected at substantially perpendicular in the flow directions; and the layer at an end portion in lamination direction is a layer in which the cooling fluid flows; wherein said cooling fluid and said being-cooled fluid are in substantially parallel to each other; and a groove is formed for maintaining a sealing rubber on a surface opposing to cooler of said integrated casing forming the refrigeration chambers, whereby sealing up by means of the sealing rubber between the upper surface or the lower surface of said cooler and said integrated casing; wherein said first to said third coolers are formed in the same shape; wherein an inlet guide vane apparatus or a suction throttle-valve is disposed on a suction side of said first-stage impeller; and wherein said integrated casing is made from a cast.
According to the present invention, also for accomplishing the object mentioned above, there s provided a turbo compressor, comprising: a first rotation shaft, being connected to a motor shaft; a second rotation shaft, on both end portions of which are attached a first-stage impeller and a second-stage impeller; and a third rotation shaft, on one end of which is attached a third-stage impeller, wherein said first, said second and said third shafts are disposed in parallel to one another, and an operation gas is guided from said first-stage impeller, said second-stage impeller, and next to said third-stage impeller, further comprising: an integrated casing accommodating the all impellers and all rotation shafts therein; a flange opening portion of a circular shape on an impeller portion of the integrated casing, in axial direction of the rotation shaft, wherein the impeller is made detachable from said opening.
According to the present invention, in the turbo compressor, as described in the above: wherein in a lower portion of the integrated casing, in which the impeller is accommodated therein, is accommodated a cooler for cooling the operation gas, being compressed by the impeller, and the cooler is accommodated in the integrated casing, so that a direction of flow of the operation gas in the cooler is perpendicular to a direction of the rotation shaft; and wherein a length of each portion of the compressor is within a length of a portion of said casing, where said cooler is accommodated, in a direction perpendicular to an axis thereof.